308 Beer, Scientifically and Socially Considered. [July, 



mash, whilst the pole to which they are attached rotates horizontally, 

 so that the whole contents of the tnn are thoroughly beaten and mixed. 

 This operation has really a very novel and interesting appearance 

 to one who has never witnessed it before. As the observer stands 

 looking into one of the openings in the mash-tun, nothing appears to 

 be going on in the mash so long as the beaters are on the side opposite 

 to him, but presently a slight undulation of the surface announces 

 their approach. Slowly the pole, with its beaters, moves round 

 towards the side where the spectator stands ; the undulations become 

 more marked, until at length the revolving arms make their appear- 

 ance, breaking up the surface and creating a great commotion. After 

 the round is completed, the apparatus is stopped, and the mash is 

 left undisturbed for some time, the process being repeated at regular 

 intervals. But there is another rotating apparatus of a very simple 

 kind attached to the central spindle., and that resembles in appearance 

 and action the horizontal discharge-pipe at the back of a watering 

 cart. It is in fact a copper pipe, of a suitable shape, with holes 

 drilled along its whole length, and may be seen on looking through 

 one of the openings in the mash-tun (see Plate II.). After the 

 strongest portion of the " wort " is obtained from the malt by the 

 mashing process already described, it is dosed with a shower of hot 

 water, poured upon it from this rotating pipe, which is called the 

 "sparge,"' the operation being termed ''sparging." At the bottom 

 of each mash-tun there are four pipes through which the wort is 

 drawn off, and these pipes lead into a main which conducts the 

 liquid into the " underback," an intermediate vessel between the mash- 

 tun and the boiling copper, where, as the name indicates, the process 

 of boiling with hops is carried on. 



The boiler is an open copper cauldron or kettle, set in brick, and 

 heated from beneath. It has a capacity of about seventy barrels ; 

 and when the requisite quantity of hops is deposited in it, the wort 

 is admitted through a pipe connected with the "underback," into 

 which the liquor has been run from the mash-tun, as already de- 

 scribed. The feed-pipe bends over the opening of the copper, whilst 

 at the bottom of the same vessel is another pipe, through which, 

 when the boiling is complete (and the liquor is well stirred during 

 the process), the boiled wort, or unfermented beer, is run off into the 

 " hop-backs.'' These, again, are intermediate vessels, square wooden 

 cisterns, with false bottoms, which act as a sieve, and the object of 

 running the liquor into them is to free it from the spent hops with 

 which it is accompanied, before cooling and fermentation. 



A word concerning the spent hops. After the liquor has been 

 allowed to drain from them in the hop-backs, they are placed in 

 hydraulic presses to extract any wort that may still remain in them, 

 and are then packed and sold as manure. 



From the "hop-backs" the wort runs into the refrigerators, 



